Electron tube socket having spark gap structure

ABSTRACT

This invention relates to an electron tube socket which comprises a single insulation base body formed with a plurality of pin inserting through-holes positioned peripherally and spaced from each other. Terminal contacts each having a pin receiving portion are inserted into the pin inserting holes. An integral conductor portion is provided on each terminal contact and protrusions are formed in the conductor portions at the lower sides thereof. A grounding plate is positioned away from the conductor portions of said terminal contacts with a raised protrusion formed thereon. The grounding plate is positioned so that the protrusion formed on each of the terminal contacts overlies the protrusion on the grounding plate and lie along an axis which intersects or crosses the protrusion on the grounding plate when viewed in plan. In this way, an arc gap is formed between the overlying points of each terminal contact protrusion and grounding plate protrusion at the point of intersection of the longitudinal axis in plan view of the protrusions on the terminal contact and the grounding plate.

United States Patent [1 1 Suzuki Oct. 28, 1975 ELECTRON TUBE SOCKETHAVING [73] Assignee: 'Showa Musen Kogyo Kabushiki Kaisha, Tokyo, Japan[22] Filed: Apr. 10, 1974 [21] Appl. No.: 459,638

[30] Foreign Application Priority Data Apr. 25, 1973 Japan 48-49954 [52]US. Cl 313/51; 313/325; 339/14 T; 339/143 T; 339/193 R [51] Int. Cl.H01R 23/40 [58] Field of Search 313/51, 325, 313, 318; 317/69, 70;328/8; 315/35, 36; 339/14 T, 143 T, 193 R [56] References Cited UNITEDSTATES PATENTS 3,240,980 3/1966 Schuster 313/325 X 3,251,016 5/1966Manetti et al. 313/51 X 3,423,720 l/l969 Pittman 339/143 T X 3,748,5217/1973 Wright et al 313/325 3,805,108 4/1974 Suzuki 313/325 X PrimaryExaminer-Siegfried H. Grimm Attorney, Agent, or Firm-Stevens, Davis,Miller & Mosher [57] ABSTRACT This invention relates to an electron tubesocket which comprises a single insulation base body formed with aplurality of pin inserting through-holes positioned peripherally andspaced from each other. Terminal contacts each having a pin receivingportion are inserted into the pin inserting holes. An integral conductorportion is provided on each terminal contact and protrusions are formedin the conductor portions at the lower sides thereof. A grounding plateis positioned away from the conductor portions of said terminal contactswith a raised protrusion formed thereon. The grounding plate ispositioned so that the protrusion formed on each of the terminalcontacts overlies the protrusion on the grounding plate and lie along anaxis which intersects or crosses the protrusion on the grounding platewhen viewed in plan. In this way, an arc gap is formed between theoverlying points of each terminal contact protrusion and grounding plateprotrusion at the point of intersection of the longitudinal axis in planview of the protrusions on the terminal contact and the grounding plate.

4 Claims, 6 Drawing Figures U.S. Patent -Oct.28, 1975 Sheet1of33,916,238

FIG. I

ll l2l49 l6 l3 U.S. Patent Oct. 28, 1975 Sheet2 of3 3,916,238

US. Patent Oct. 28, 1975 Sheet3 of3 3,916,238

FIG. 5

' II II ELECTRON TUBE SOCKET HAVING SPARK GAP STRUCTURE BACKGROUND OFTHE INVENTION This invention relates to electron tube sockets and isparticularly concerned with a socket provided with a spark gap todischargeabnormally high voltage when it appears.

In the hitherto known conventional electron tube socket of this type, adischarge device called an arrester is provided separately from thesocket, which brings about a disadvantage that manufacturing costbecomes high and additional work is required in the assembling process.

A socket having an interior discharge portion has been already proposed,which is composed of an insulation base body having a plurality ofradially extending flat conductor portions of terminal contacts and agrounding ring plate formed with the same number of projections as thatof the conductor portions, each of the projections being positioned inopposition to or faced to each of respective conductor portions tothereby form arc-over gaps between the projections and the conductorportions. The socket of this construction has a drawback in that thecentered relation positions between the conductor portions of contactsand the projections of the grounding plate may be disarraged, wherebydifficulties are encountered with for obtaining spark gaps each having apredetermined gap dimension. Additionally, because the grounding plateis punched from a brass plate and therefore ears and edges are likely tobe formed at the pointing portions of the projections, the voltage atwhich the discharge occurs may vary depending on the individualdischarge portions.

An object of the present invention is to provide an improved socket fromwhich all the above mentioned disadvantages are substantiallyeliminated.

Another object of the present invention is to provide an electron tubesocket comprising a grounding plate and conductor portions of terminalcontacts, both having respective protruding zones which are positionedso as to intersect each other to thereby form arc-over gapstherebetween.

The above and other objects as well as novel features and advantages ofthe invention will become more apparent from the following descriptionof a preferred embodiment of the invention. The description makesreference to drawings.

Brief Description of Drawings FIG. 1 shows a socket according to theinvention in a vertical sectional view;

FIG. 2 is a partial perspective view of the socket to show thepositional relationship between a conductor of a terminal contact and agrounding plate;

FIG. 3 is a top plan view of an insulation base body;

FIG. 4 is a bottom plan view of an insulation base body;

FIG. 5 is a top plan view of an insulation plate; and

FIG. 6 is a bottom plan view of the same.

Detailed Description of Preferred Embodiments In the drawings, referencenumeral 1 indicates an in: sulation base body having a guidethrough-llble 2 formed at the center portion thereof. The base BBQ? 1further has an annular protrusion 3 integrally formed at the uppersurface thereof. A plurality of pin inserting openings 4 are formedthrough the base portion along the inner circumference of the protrusion3 with constant distances between the adjacent openings 4. Additionally,a corresponding number of radial grooves 6 are formed in the lowersurface of the base body 1, which grooves 6 are insulated from thecentral guide hole 2 by thin walls 5 and opened in the outer peripheralsurface of the base body 1.

Each of the grooves 6 are individually communicated with the associatedpin inserting openings 4. Reference numeral 7 denotes a terminalcontact, which has a conductor portion 8 extending flatly from the lowerend of the contact 7 and an integral terminal portion 9 bent from theflat conductor portions 8, as is shown in FIG. 2. It is to be noted thatthe conductor portion 8 has a protrusion or protruding zone 10 formed atthe lower surface and extending longitudinally. Reference numeral 11indicates a circular insulation plate which has the same outer and innerdiameters as the insulation base body 1 and is formed with ribs 12 atthe upper surface thereof, which ribs 12 being adapted to engage thegrooves 6. The insulation plate 11 has a concaved annular groove 13formed at the lower surface, as is shown in FIGS. 1 and 6. A pluralityof through-holes 14 are provided at the intersections of the grooves 6and 13. Reference numeral 15 denotes a grounding plate which consists ofan electrically conductive ring like plate, as is shown in FIG. 2, andhas a protrusion 16 projecting upwards and integrally formed at themiddle portion and a terminal 15 for connecting it to a groundingcircuit.

One of the contacts 7 serves for the application of a high voltage suchas for the connection of the focus terminal of a cathode ray tube, forexample. A shield box 17 encasing the terminal portion 9 of the contact7 for high voltage is formed by the insulation base body 1 and the plate11.

The assembling of the socket according to the present invention can becarried out as follows:

At first, the contacts 7 are inserted into the pin inserting openings 4from below with the conductor portions 8 being accommodated within thegrooves 6. The grounding plate 15 is fitted into the concaved annulargroove 13 of the insulation plate 11. Next, set screws (not shown) areinserted into the holes 18 extending through the insulation base body 1,plate 11 and grounding plate 15, and finally the assembly is held in arigid construction by means of nuts (not shown) threaded onto the setscrews.

As can be seen in the drawings, the grounding plate 15 is positionedaway from the conductor portions of said terminal contacts with a raisedprotrusion formed thereon. The grounding plate is positioned so that theprotrusion formed on each of the terminal contacts overlies theprotrusion on the grounding plate and lie along an axis which intersectsor crosses the protrusion on the grounding plate when viewed in plan. Inthis way, an arc gap is formed between the overlying points of eachterminal contact protrusion and grounding plate protrusion at the pointof intersection of the longitudinal axis in plan view of the protrusionon the terminal Contact and the grounding plate.

By cohsil ucting the socket in the above described mann ef Qlc-over gapsG having a predetermined gap 'cli'r fielfifig fl are formed between theprotrusion 10 of the conductor portions 8 of the contacts 7 and theprotrusion 16 of the grounding plate 15. When a potential differencebeyond a predetermined value appears between the conductor portions 8and the grounding plate 15, the gaps are fired to discharge theovervoltage.

As is obvious from the foregoing description, in the electron tubesocket according to the invention, the protrusions 16 and 10 areprovided by an embossing work on the grounding plate and the conductorportions 8 ofcontacts 7, respectively, to thereby form areover gapsbetween the protrusions 16 and 10. In other words, since the arc-overgaps are formed interiorly of the socket by assembling the groundingplate therein, the socket having the discharge portions or arresters canbe manufactured compact and the number of the parts for the socketassembly can remarkably be reduced as compared with the conventionalsockets. Further, even if disarrangement should occur in the positionsof the grounding plate 15 and the contacts 7, the arc-over gaps G formedby the protrusions 16 and 10 will remain unchanged. Neither ears noredges can be produced at the pointing portions of the protrusions ofgrounding plate 15. Those protrusions 16 and 10 can be easily formed byan embossing work or process.

Although the invention has been described and illustrated with referenceto a preferred embodiment, it should be obvious for those skilled in theart that many modifications and variations may be made in the form of'the invention without departing from the spirit and scope of theinvention as defined in claims.

What is claimed is:

1. An electron tube socket comprising an insulation base body formedwith a plurality of holes positioned peripherally and spaced from eachother, a plurality of terminal contacts each having pin receivingportion inserted into one of said holes and having an integral conductorportion extending radially on the lower surface of said base body with alongitudinal protrusion formed along the conductor portion on the lowerside thereof, a grounding plate positioned so as to be spaced from saidconductor portions of said terminal contacts, and a protrusionintegrally formed in said grounding plate through its entire length andpositioned so that when viewed in plan the longitudinal axis of saidprotrusions on said conductor portions are seen to intersect theprotrusion on said grounding plate at points of intersection to formarc-over gaps between said protrusions on said conductor portions andthe protrusion on said grounding plate at said points of intersection.

2. An electron tube socket according to claim 1, further comprising aninsulation plate for pressing said conductor portions against said basebody and positioning said grounding plate spaced from said conductorportions.

3. An electron tube socket according to claim 2, wherein radial groovesare formed in said base body for fitting said conductor portionstherein, and said insulapoint of intersection when viewed in plan.

1. An electron tube socket comprising an insulation base body formedwith a plurality of holes positioned peripherally and spaced from eachother, a plurality of terminal contacts each having pin receivingportion inserted into one of said holes and having an integral conductorportion extending radially on the lower surface of said base body with alongitudinal protrusion formed along the conductor portion on the lowerside thereof, a grounding plate positioned so as to be spaced from saidconductor portions of said terminal contacts, and a protrusionintegrally formed in said grounding plate through its entire length andpositioned so that when viewed in plan the longitudinal axis of saidprotrusions on said conductor portions are seen to intersect theprotrusion on said grounding plate at points of intersection to formarc-over gaps between said protrusions on said conductor portions andthe protrusion on said grounding plate at said points of intersection.2. An electron tube socket according to claim 1, further comprising aninsulation plate for pressing said conductor portions against said basebody and positioning said grounding plate spaced from said conductorportions.
 3. An electron tube socket according to claim 2, whereinradial grooves are formed in said base body for fitting said conductorportions therein, and said insulation plate is formed with ribs fittedinto said grooves.
 4. An electron tube socket according to claim 2wherein the longitudinal axis of the protrusions on said conductorportions are substantially perpendicular with said protrusion on saidgrounding plate at said point of intersection when viewed in plan.